The Quantum Vapor—commonly referred to as Bang Baby gas—was the mutagenic gas that was responsible for the mutations of hundreds of people in Dakota. It was produced by Alva Industries.
Background information
The Quantum Vapor—so named in "Junior"—is based on Quantum Juice of Milestone Media comics. After an all out gang brawl erupts at the Dakota dock, Police arrive and warn everyone to cease fighting and remain where they are. Everybody scatters and ignores warnings, forcing the Police to fire down a canister of tear gas. However, the canister drops down right next to large containers of Edwin Alva's Quantum Vapor, causing an explosion and the release of a cloud of purple gas. Everybody who breathes it in begins coughing, then exhibiting strange physical reactions. The incident is dubbed the Big Bang, with those who survived obtaining metahuman powers. Following the Big Bang, the mayor attempts to keep the attention off Alva Industries due to the company's importance to Dakota, hiding from the public the fact that Alva was responsible.